To maintain their bone and muscle mass, astronauts need to work out two hours every day. CSA Astronaut and Commander Chris Hadfield shares his workout routine. Video courtesy Canadian Space Agency.

This transcript has been automatically generated and may not be 100% accurate.

I ... I ... weightlessness is called ... shares of the things you just get you ... anywhere else ... by the ... time ... but ... it doesn't come free ... with the ... car's load in your body is getting ... a little easier ... your muscles start to salt your ... posts are getting really sore back in your body ... so to stay strong to ... spacewalk white space or ... receive strut of what we get home again ... we have to just ... have to do it better but he's strong ... we did it and there are six sets of parents these days ... including teach you ... treat deleveraging ... rate cuts such ... tests ... I ... I ... I ... I ... I ... I ... I ... the the the ... I ... I ... I ... I ... I ... I ... I ... I ... I ... the excess ... write whatever might ... I'm ...